In the assembly of conduits intended for high temperature and high pressure applications, misalignment is a significant problem. Most conventional misalignment fittings are ball and socket designs intended for low pressure and/or low temperature applications, such as for underwater or subterranean pipelines. These designs do not handle misalignment in high pressure, high temperature conduit systems properly. Most conventional fittings tend to straighten the conduits and transmit the misalignment into an assembly stress. This leads to accelerated tube failures.
Misalignment fittings adapted for high pressure and/or high temperature applications have tended to result in leaks during use. In these designs, two spherically shaped surfaces are mated together by a threaded connector which surrounds the conduit and compresses the spherical surfaces when tightened. Unless the spherical surfaces are perfectly machined, this design does not seal properly. The fitting design described by Wakefield in U.S. Pat. No. 4,103,937 is an example.
Furthermore, conventional couplings adapted for high pressure and high temperature applications are difficult to assemble in limited access areas and often require special tools, as does the fitting described by Wakefield ('937).